Described below is a method used in radio communications systems to ensure that transmissions between neighboring nodes are controlled.
In radio communications systems beyond 3G (3rd Generation Wireless Mobile Communication Technology) subscribers will have the opportunity to choose from a plurality of services provided from network operators when using UEs (User Equipments). Additionally, as the number of UEs increases steadily, network operators have to ensure that radio resources are available so that requests for services can be served and no degradation of the requested services occurs due to lack of radio resources.
As it is also becoming all the more important for radio resources to be available, RRM (Radio Resource Management) has been implemented in order to allocate and manage radio resources in radio communications systems. In order to reduce the amount of traffic generated in a radio communications system by radio resource requests, RRM is distributed throughout the system. In this way, the radio communications system is divided into well defined areas, each area having an assigned RRM unit for managing and allocating radio resources.
However, this requires that the numerous RRM units within the radio communications system be highly co-ordinated so that the allocation and the management of the radio resources can be performed efficiently, promptly and without degradation to a requested service.
Furthermore, in the event that the number of radio resources available to a RRM unit is not adequate and in order to avoid having to reduce the efficiency of the radio communications system by either rejecting a service request or accepting it with a reduced quality of service, the RRM unit has to request additional radio resources from neighboring RRM units.
Additionally, apart from requests for services that require radio resources, radio resources must always be available for certain operations that might occur in the radio communications system. For example, when a UE located within a defined area, for example a cell, under the control of a RRM unit moves to another defined area which is under the control of a further RRM unit, i.e. a handover operation is to be executed, radio resources have to be available in order to enable the handover to proceed. Such a procedure leads to an increase in the amount of signalling present as apart from the signalling of radio resource requests between the RRM units, signalling between the UE and the node controlling the area in which the UE is going to enter, known also as the target node, has to be executed as well as signalling between the node actually controlling the UE, also known as the source node, and the target node. All this signalling requires radio resources to be available in order to allow such an operation to be executed efficiently and in a timely manner.
The need to generate requests for radio resources at the RRM unit and then transmit them to neighboring unit and then wait for a response, further reduces the efficiency of the radio communications system. Moreover, as long as the radio resources are not available, the RRM unit will transmit such requests, increasing the amount of traffic present, further reducing the efficiency.
A need therefore exists for a technique that resolves the above mentioned issues as well as providing a way of controlling and managing the allocation of radio resources by RRM units in a manner that balances the needs and requirements of UEs present with the radio resources available without causing undue loss of efficiency within the system. Furthermore, a need exists for such a technique to manage the available radio resources and resolve the above mentioned issues in a dynamic manner in order to guarantee a high system efficiency and a high quality of service as well as reducing the amount of signalling traffic being propagated through the radio communications system. A need furthermore exists for an apparatus that can implement such a technique.